FIG. 2.

Comparison of amino acid sequences for SUMO-1, SUMO-2, and SUMO-3 isolated as IE2-interacting proteins from a human B-lymphocyte cDNA library. The amino acid sequences of SUMO-1, SUMO-2 (hsSmt3A), and SUMO-3 (hsSmt3B) isolated in this study were aligned. Residues that are identical in either two or three of the proteins are boxed. The arrow after the double-glycine motif indicates the position of proteolytic cleavage for conjugation. The numbers in parentheses are the numbers of amino acids presumably conjugated to the substrates.